Web feeding means for container forming apparatus



L. s. EATON April 28, 1953 WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 50, 1948 s Sheets-Sheet 1 I N V EN TOR. Lew: B, Eafin ATTORNEY April 28, 1953 L. B. EATON 3 WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Filed March 50, 1948 5 Sheets-Sheet 2 INVENTOR. Gav/.1 3 6275'? BY ATTORNEY 5 1. Qum- N NH RN April 28, 1953 L. B. EATON I WEB FEEDING MEANS FOR CONTAINER FORMING ARPARATUS Filed March 50, 1948 5 Sheefcs-Sheet 3 INVEN TOR. 1991-11! 8 E a'fin ATTORNEY April 28,1953 LTB. EATON 2,636,730

' WEB FEEDING MEANS FOR CONTAINER-IFOIRMIIINGI APPARATUS Filed March 30. 1948 s -"snbts sh-ek 4 IIIIII April 28, 1953 L, B, A ON 2,636,730

' WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS- Filed March so. 1948 I 5 Sheeta+$fieet a uvvzzvrom,

' ATTORNEY Lewis 3 Patented Apr. 28, 1953 WEB FEEDING MEANS FOR CONTAINER FORMING APPARATUS Lewis B. Eaton, Quincy, Mass., assignor to Pneumatic Scale Corporation,

Limited, Quincy,

Mass., a corporation of Massachusetts Application March 30, 1948, Serial No. 17,946

. 9 Claims. (01. 271-213) This invention relates to containerforming apparatus. 1

i In general the object of the invention is to provide a novel and improved packaging machine whereina printed web of flexible sheet material,

such as heat scalable printed paper, is utilized to produce successive filled and sealed containers in a rapid, efficient and commercially acceptable manner and wherein novel provision is made for controlling the feeding of the web to effect registration of the successive printed sections of the web with relation to the container forming mechanisms within tolerances permitted by the commercial acceptability of the packages produced. In its preferred embodiment the invention is embodied in a tea-bagging machine.

LWithythis general object in view and such others as may hereinafter appear, the invention consists in the packaging apparatus and in the variousstruotures, arrangements and combinations of parts hereinafter described and particu-- larly defined in the claims at the end of this specification.

.:In the drawings illustrating the preferred embodiment of the'invention, Fig. 1 is side elevation of a packaging machine embodying the present invention; Fig. 2 is a front elevation of the lower ;?portion of the machine shown in Fig. 1 and illustrating the web advancing mechanism; Fig. 3, is a side elevation of a portion of the con trol mechanism for the web advancing mechanism as viewed from the right of Fig. 2; Figs. 4 and 5 are detail views in plan and front elevations respectively of the web advancing grippers;

Fig. -6 is a plan view detail of a cam operated switch forming a part of the control mechanism; Fig. 7 is an electrical wiring diagram for the control mechanism; Fig. 8 is a front elevation of arcompleted container and adjacent sections indicating the length of the normal advance and the. advance with a corrective stroke relativ to the predetermined length of a container section or distance between the printed indicia on the web; Fig. 9 is a plan view of the gripper units as View from the line 9-9 of Fig. 2; and Fig. 10 is a detail view in cross section taken on the line Ill-l0 of Fi 1.

In general, the present invention contemplates package forming apparatus for making individual packages wherein an elongated web of container forming material is intermittently advanced to folding, filling and sealing mechanisms to form a strip of connected packages, and then to cutting mechanism for severing the strip through sealed connecting portions to form individual packages. Y I I In accordance with the present invention provision is made for controlling the intermittent linear advance of the web into operative position to the package forming and severing mechanisms in accordance with substantially equally spaced printed indicia on the web defining the length of individual container sections whereby to assure registration within predetermined tolerances of successive printed sections with the package forming and cutting instrumentalities irrespective of variations in the web induced by variations in the humidity and other conditions of operation.

In the illustrated embodiment of the invention the mechanism for controlling the intermittent linear advance of the web includes a detecting element arranged to cooperate with the spaced indicia upon the Web during. the linear movement thereof and means responsive to said detecting element for varying the linear stroke of the advancing mechanism in accordance with the position of the web at a predetermined time in the cycle during such advance.

In practice, and in accordance with the present invention, the normal uncorrected stroke of the web advancing mechanism is preferably arranged to advance the web a distance slightly less than the predetermined length of a package section or slightly less than the distance between successive indicia, and the correcting stroke of the web advancing mechanism is preferably arranged to advance the web a distance slightly more than the predetermined spacing between successive indicia except in those unusual instances where the web expansion or contraction equals its correction. Thus, the web advancing stroke is continually being increased or decreased relative to the predetermined average spacing, as controlled by the detecting means, the cumulative effect of successive shortened ornormal advancing strokes causing the spaced indicia to creep up relative to the detecting means and the cumulative effect of successive lengthened or correcting strokes causing the spaced indicia to creep down relative to the detecting means,

"i so as to maintain the advance of the web within predetermined limits and in operative relation to the container forming and severing mechanisms, the correcting stroke occurring during the same cycle of advance in which the detection is made.

The present invention is herein illustrated as embodied in a duplex type of packaging machine wherein two printed webs are concurrently advanced into operative position to the bag forming and severing mechanisms and, in accordance with another feature of theinvention provision cial machine for making tea bags from an clonev gated web or strip of thin paper in accordance with the method disclosed in the United States patent to Patterson, No. 2,272,530 issued February 10, 1942. In general the machine comprises an improvement upon the apparatus disclosed in the United State patent to Patterson, No. 2,385,229 issued September 18', 1945'. As herein shown, such machines may be constructed in duplex form for simultaneously producing two strips of connected and filled bags and for severing the strips through sealed portions thereof to form individual tea bags.

In the operation of such a machine, and as illustrated in Fig. l, a web of heat scalable paper lllis withdrawn from a supply roll 2 thereof and advanced over container forming mechanism is which operates to fold the web longitudinally along a medial line to bring together the two half sections of the Web preparatory to forming a strip of connected bag sections it. The paper is prefera'bly drawn over the forming mechanism it by vertically and horizontally reciprocable gripping and advancing mechanism 2c operative to nominally advance the strip substantially one bag length each cycle of operation and to present the strip in operative relation to the sealing mechanism, indicated generally at 22, and which i arranged to apply heat and pressure to seal the strip simultaneously along a transverse zone 24 and: an adjacent longitudinal zone 26 during each sealing operation to form a series of connected package sections closedon one side-by the folded edge 2'8 and heat sealed along the remaining side and at the top and bottom.

The paper being unwound from the supply roll lZand advanced by the gripper mechanism 20 is arrangedto pass over a takeup roll 59 mounted for axial movement in a bracket 65 and then over a roller II which may be intermittently driven in timed relation to the linear advance of the gripper mechanism. The movable takeup roller 59 is yieldingly urged outwardly in its support in bracket 65 by springs ti and is capable of m ward movement during the unwinding operation in order to maintain the web relatively taut and to take up any slack between the gripper mechanism and the supply roll. Provision may also be made for preventing inadvertent unwinding of the web from the supply roll 12 by providing the latter with suitable retarding means such as a friction brake or bearing, indicated at 5i.

.lProvision is also made, in such prior machines for depositing successive charges of the commod ity intosuccessive of the uppermost bag sections as they are being formed by feeding mechanism indicated generally at 39, the feeding mechanism operating in timed relation to the operation of the strip advancing and heat sealing mechanisms 26, 22 respectively, and, in the operation of the ma chine,- the open top of a package which has been provided. with a charge of the commodity during one cycle; of operation is closed during a. succeeds 4 ing cycle. Thereupon, the strip is intermittently advanced to cutting mechanism, indicated generally at 32 which operates to sever the strip through successive transverse sealed portions 24 to form individual filled and sealed packages.

The machine illustrated and described in the l atterson Patent No. 2,385,229 above referred to was particularly designed for producing paper tea bags made from a web of plain, unprinted heat scalable paper, .and such machines are at the present time extensive successful commercial use. However; when printed webs are used in a machine having a linear Iweb advancing mechanism arran edto advance the web a fixed distance at each cycle of operation, that is the length of a package section, it is diflicult to maintain correct registration of successive printed package sections withthe package fOllI'llllg instrumentalities since, in practice, the sections may vary due'to inaccuraciesin printing, atmospheric conditions,

stretching of the web during withdrawal or pos-z.

sible' slippage of the web. Thus, in the operation of such prior machines on a printed web, any slight variations in the printed sections will be cumulative so that eventually the Web will depart from registration with the package forming and; cutting mechanisms.

In the illustrated embodiment of the invention, each web gripping and advancing mechanism 20 includes a pair of opposed cooperating gripper units 49, 42 mounted to be horizontally recipro cated into and out of gripping engagement with the web, and, to be vertically reciprocated to advance the web each cycle of operation. In practice, the linear stroke of the grippers is initially adjusted so as to normally advance the web a distance slightly less than the package length or distance between successive substantially equally spaced markings 44 on the web. As herein shown, each gripper 40, 42 is also mounted for pivotal movement in its'supporting member to be capable of being rocked while in gripping engagement with the web to eiiect advancement of the web beyond the normal stroke when actuated by control mechanism responsive to the position of the markings M at a predetermined time in the web advancing cycle of operation so as to eilect a correction in the linear advance of the web duning the same cycle in which the lack of regi'stra-, tion is detected. In general, the control mechanism includes a photo-sensitive detector, indicated generally sit-46, arranged to cooperate with the spaced markings 44 during the advancing cycle of operation; a timing switch 48 arranged to render the detector operative at a predetermined time in the web advancing cycle, and a solenoid operated member 50 arranged to cooperate with the grip pers to efifect advancement of the grippers beyond the normal stroke when actuated by the detector mechanism. In practice, the photo-sensitive de-' tector is placed relative to the web so that the light beam image is concentrated on the edge of the web at a point approximately halfway between two markings M when the web is at rest as illustratedin Fig. 1, Thus, during intermittent advancement of the web the light beam image may be intercepted by the marking at about the halfway point in it advance, as illustrated in Fig. 7. The detector unit herein illustrated is arranged to be excited to effect a corrective stroke only when the light beam is intercepted by the mark during theme arming period that is, when the circuit is closed by the timing switch 48, and then'only when the beam is out off by the leading edge of a rapidly passin mark. If the iii-grudges crease the I stroke.

smear/so not'appearduring the scanning period, no correction is made. and, if the beam falls directly. on the mark and the mark then passes by so that the beam then fall on the relatively lighter'background of the web during the scanning period, no

correction is made. I

In the operation of the apparatus, assuming that the average package length is approximately 2 /;inches, for example, successive uncorrected or shortened linear strokes, adjusted to advance the'web about of an inch less than the average package length, or 2% inches, will effect a gradual or cumulative rising or .creepq ing up of the marks 44 r'elativeto the light beam until a point is reached where the light beam is intercepted by a mark moving therepast, and, when this occurs, a correction stroke is applied during the same cycle in which such detection is made, to advance the web" a distance slightly more, approximately ez'of an inch more, for example, than the average length of a package section, making the total advance about 2%} inches. Thus it will be seen that the web advancing stroke is either increased or decreased relative to the predetermined package length, continually between predetermined limits, unless the variation in the web cause no" detection whereby to obtain registration of successive package sections with the container forming mechanism and cutting mechanisms within the predetermined permitted tolerances. g Referring now to Figs. 1 and 2 for a more detailed description of the web advancing apparatus, as therein shown, opposed gripper units 40, 42 are arranged to be horizontally reciprocated in brackets 52, 54 respectivelythe latter being adjustably clamped upon vertical rods 56, 58 supported for vertical reciprocation in suitable bearings provided in the machine frame. The rods 56 and 58 are arranged to be vertically reciprocated' in timed relation to theop'eration of the package forming mechanisms by a cam 60 mounted fast on the main cam shaft I60, and, as herein shown, provision is made for initially adjusting the effective stroke of the cam in order to adjust the linear advanceof the grippers with relation to the length of package sections of the web. The rods 56, 58 are secured at their lower ends to 'a pair of yoke shaped tie pieces 62 only one of which is shown, the tie piece 62, having a central slotted portion 64 for cooperation with a slide block 66 mounted on one end of an eccentric stud 68 carried in a lever 'IIifast on arocker shaft I2, the eccentric stud being rotatably adjustable in the lever!!! as shown in Fig. 10. The eccentric end of the stud 68 is provided withfa roller 14 cooperating with the fixed cam path of the cam 60.

' With' this construction it will be seen thatby rotary adjustment of the eccentric stud-68 the effective length of the lever arm may be varied, rotary adjustment in one direction oper-' ating, to increase the distance from the center of the rocker shaft 12 to the center of the roller {I4 .110 decreasethe effective stroke, and, rotary adjustment in the opposite direction operating to decrease the distance from the center" of the rocker shaft to the center of the roller to in- Thus, the linear movement of the gripper'units may be initially adjusted so as to effect a linear advance of the web a distance slightly'less than the average spacing between successive markings 44. It will be understood that .the gripper carrying bracketsfl, may also be adjusted .on their respective rods 6 56, 58 to align the cooperating gripper units"; 42 for cooperation with "successive transverse sealed portions 24 of the web.

While the above description has been confined thus far to the operation of one pair of cooperating gripper units 40, 42 for advancing a web of container forming material into operative re-. lation to the bag forming instrumentalities, it will be understood that in the duplex machine herein illustrated, an identical and simultaneously operating pair of gripper units 400, 420 are carried by the brackets 52, 54 respectively, as illustrated in Fig. 9, the brackets being also adjustably supported upon similar vertical rods 560, 580 arranged to be vertically reciprocated by the cam 60 through similar connections including a lever arm fast on the rocker shaft 12 so that in operation, the gripper units are simultaneously operated to cause the webs to be advanced into operative relation to their respective container forming. filling and severing mechanisms.

I As illustrated in Figs. 2 and 9, each gripper unit 40, 42 and their corresponding units 400, 420 are supported for horizontal reciprocation upon individual rods 16 slidingly carried in the brackets 52, 54, each rod being provided with a coil spring "I8 interposed between a portion of its supporting bracket and a collar 80 adjustably secured to the rod, the springs being arranged to urge the grippers inwardly into cooperating engagement with their opposing grippers and the container forming webs. The rods I6 of each unit arejoined at their outer ends by a tie piece 82 and each tie piece carries a roller 84 arranged to cooperate with elongated cams 86 secured to vertical cam shafts 88, 90 respectively. Thus, in the operation of the machine, the gripper units 40, 400 and 42, 420 are horizontally reciprocated simultaneously into and from engagement with the webs'fthe springs I8 effecting a yielding engagement therewith and the cams operating to positively separate the grippers. The vertical cam shafts 88, 90 are arranged to be rotated from the main cam shaft I60 by connections including bevel gears 92, 84 to the vertical shaft 88, bevel gears 96, 98 to a horizontal shaft I00, and a second set of bevel gears to the vertical shaft 90.

As above stated, the cooperating gripper units 40, 42 and the corresponding pair of cooperating gripperunits 400, 420 are mounted for pivotal movement so that when actuated by the control mechanism, the grippers effect an advance of the web a distance slightly more than that of the predetermined reciprocating stroke of the grippers, and, as best shown in Figs. 4 and 5, the gripper unit 40 includes a web engaging member I02 mounted in a retaining member I04 supported upon two spaced rods I06, I 08 slidingly mounted in rocker members H0, H2 supported for pivotal movement in a U-shaped bracket II4 secured to the end of the horizontally reciprocable rod I6. The rod I6 is reduced in diameter at the connecting end and the U-shaped bracket H4 is assembled against the shoulder formed by the reduced diameter and is retained on the rod by a block I I6 keyed to theend of the rod,'the bracket being secured to the block to prevent rotation of the bracket. The rocker members 'I I0, I I2 are fitted between the side faces of the block H6 and the arms .I I8, I20 of the IJ-shaped bracket and are pivotally mounted therebetwee'n upon spaced axially aligned pins I22, I24 extending from thearms II8, I20 respectively and pins I26, I28 extending from opposite sides offthe It'will beu'nderstood that the'characteristics of the preferred detector unit 46 ar such that if 'the light beam is directly in alignment with a registration mark 44 when the timing switch 48 is closed, thus indicating substantially uniform registration of the package sections with the container forming'mechanisms, the relay I16 will not be actuated and also if the light beam is directed on'the mark and then passes from the mark to the relatively lighter surface of the web material during the scanning period, also indie cating substantially uniform and commercially acceptable registration of the package sections, the relay will not be actuated to efiect additional advancement of the web. The only time the detecting unit will respond to the passage of the moving web is when the light beam is first directed onto the relatively light surface of the web material when the timing switch is closed and is then rapidly interceptedby the passage of a relatively darker surface registration mark during the scanning period, such position being indicated generally in Fig. '7 wherein the switch contacts I80, l82 are closed and the light beam is about to be intercepted by a mark ,44, indicating that the package sections are lagging slightly behind substantially uniform registration with the container forming and severing instrumentalities.

Upon interception of the light beam by the registration mark at such time, the relay I16 will be actuatedto close the circuit I18 to the s'ole noid I62 which is in turn energised to extend the stop bar 50 into the path of the rocker arm I48 so that as the gripper members approach the end of their normal stroke. the'web is given an additional and preferably predetermined increment of advancement byithe cooperative rocking action of the rocker members I40, .142. Thereafter, in the operation of the apparatus, the gripperunits are moved apart to disengage the web and are returned to their normal horizontally aligned position for cooperation with the next succeeding transversely sealed portion of the web during the next cycle of operation. It will thus 'be seen that the correcting action of the Web advancing mechanism occurs during the same cycle of operation that a deviation from a substantially uniform position of advancement is detected so as to assure that none of the package sections deviate from such position beyond predetermined commercially acceptable limits.

From the description thus far it will be seen that in the operation of the web advancing mechanism'successive normal or uncorrected webadvancing stokes which are slightly less than the average spacing of the printed" package sections of the-web will cause the marks to rise relative to the light beam concentrated onthe moving web and that this action will be cumulative so that eventuall-y'the mark will intercept the light beam, as described, to effect additional advancement of the web. A herein shown, similar control mechanism is provided for controlling each web of a duplex container forming machine, and includes a similar detecting unit 460, solenoid operated bar 500, and timing switch 480 so that in operation, although the web advancing mechanisms are simultaneously operated through the cam 6!), yet each web may be individually controlled to selectively effect an additional advance of the Web as determined by its individual detecting unit. Thus, the package forming webs are maintained in substantially uniform registered relation with their respective package forming mechanisms comprising the package sealing mecha;

10 nism 12, filling mechanism 30, andsevering mechanism 32 which may comprise the mechanisms illustrated and described in the Patterson Patent No. 2,385,229 above referred to, and to which reference may be had for a more come plete description of the structure and mode of operation of such mechanisms. As herein shown, successive connected filled and sealed packages advanced into operative position to th severing mechanism 32 are cut off and received. in suitable guides 390, 392 through which they are advanced by intermittently operated pusher arms 394, 396 to be delivered from the machine.

From the above description it will be seen that provision is made in the present apparatus for controlling the intermittent advance of a printed web of container forming material into operative. position to the package forming and severing mechanisms in accordance with substantially equally spaced printed indicia on the web defining the length of individual container sections, the control means being adapted to correct the linear advance of the web during the same cycle in which a deviation from the predetermined spacing is detected beyond the permitted tolerances. v

While the preferred embodiment of the inven-. tion has been herein illustrated and described it will be understood that the invention may be embodied in other forms within the scope of the following claims. a

Having thus described the invention, what is claimed is:

1. In a machine of the character described, a

combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a pair of horizontally and vertically reciprocable grippers arranged to intermittently advance the Web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation, control means including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to said control means arranged to cooperate with said grippers to increase the advancing stroke when and only when a deviation from a predetermined position beyond an allowable tolerance is detected as determined by the interception of the detecting means by the registration mark dur ing said predetermined time for advancing the Web an additional fixed increment as the grip: pers approach the endof their normal advancing stroke whereby to obtain a net advance slightly more than, the predetermined package length during the same cycle of operation in which such deviation is detected. i

2. In a machine of the character described, in combination, Webieeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a pair of horizontally and vertically reciprocable ,grippers arranged to intermittently advance the web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation, said grippers being also mounted for pivotal movement, control means including means for detecting the position of a registration mark at a predetermined time during theadvance of the web, and means cooperating with said grippers and responsive to said detecting means, when, and only. when a deviation. fromta predetermined position beyond an allowable tolerance is detected as determined by the interception of the detecting means by the registration mark during said predetermined time, for 'efiecti-ng pivotal movement of the grippers they approach the end of their normal advancing stroke to effect a longer stroke and -thus efiect an additional fixed increment of advance of the web to obtain a not advance slightly more than the predetermined package length during the same cycle of operation in which such deviation is detected.

3. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially Fl equally spaced registration marks thereon defining successive package sections, comprising :a

pair of horizontally and vertically ireciprocable grippers arranged to normally advance the web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation, said grippers being also mounted for pivotal movement, control means including a normally inoperative photo-sensitive detector arranged to cooperate with said registration marks, a timin switch for rendering said detector operative 'to detect the position of a registration mark at a predetermined time during the ad- Vance of the wehand means responsive to sai de tecting means and movable into engagement with a portion of said grippers when and only when a deviation from a predetermined position beyond an allowable tolerance is detected as determined by the interception of the detecting means by the registration mark during said predetermined time for eiiecting pivotal movement of the grippers to increase the advancing stroke as they approach the end of their normal advancing stroke and thus effect an additional fixed increment of advance of the web to obtain a not advance slightly more than the predetermined package length during the same cycle of operation in which such deviation is detected. 7

4. In a machine of the character described, in combination, web ieedingmeans iorint'ermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprisin a pair of horizontally and vertically reciprocable grippers arranged to normally advance the -web a fixed .distance s'lightly less than the predetermined package length each cycle of operation, control means including eiectro-responsive means for detecting the position of a registration mark at a predetermined time during the advance of the web, and a solenoid operatedmember responsive :to said control means arranged to cooperate with :and engage a portion oi said grippers to effect an additional advancing movement when and only whena deviation from axpredetermined position beyond an allowable tolerance is detected as determined by the interception of the detecting :mearrs by the registration mark during said predetermined "time, for eiiecting an additional fixed increment of advance of the web as the grippers approach the end of their normal advancing stroke whereby to obtain a net advance slightly more than the predetermined package length during the same cycle of operation in which such deviation :is detected.

:5. In a machine of the character described, in combination, web feeding means for intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections, comprising a pair of horizontally and vertically-reciprocable grippers arranged to normally advance the web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation, said grippers being also mounted for pivotal movement, control means including a normally inoperative photo-sensitive detector arranged to cooperate with said registration marks, a timing switch for rendering said detector operative to detect the position of a registration mark at a predetermined time during the advance of the web, and a solenoid operated member responsive to said control means when and only when a deviation from a predetermined position beyond an allowable "tolerance is detected as determined by the interception of the detecting means by the registration mark during said predetermined time for cooperation with and engageable with a pm" tion of said grippers to eiiect pivotal'inovement thereof to increase the advancing movement as they approach the end of their normal advancing stroke and thus effect an additional fixed increment of advance of the web to obtain a net ad'- vance slightlymore than the predetermined package length during the same cycle of operation in which such deviation is detected.

-6. Ina machine of the character described, in combination, web feeding means for intermittent ly advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising apair of horizontally and vertically reciprocable grippers, cam operated means for effecting vertical reciproca- Ition of said grippers, means for initially adjusting the linear stroke of said cam operated means to intermittently advance the web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation. control means including means for detecting position .of aregistration mark at a predetermined time during the advance of the web, and means responsive to said control mean arranged to cooperate with said grippers 'to effect an additional advancing movement when and only when a deviation from a predetermined position beyond an allowable tolerance is detected as determined -by the interception of the detectin means by the registration mark during said predetermined time for advancing the web .an additional fixed increment as the grippers approach the end of their normal advancing stroke whereby to obtain .a not advance slightly more than the predetermined package length during the same cycle of operation in which such deviation detected 7, In a machine of the character described, in combination, web efeedingmeans for-intermittently advancing a web having substantially equally spaced registration marks thereon defining successive package sections comprising a pairiof hori. zontally and vertically :reciprocablc grippers arranged to intermittently advance the web through a normal fixed stroke slightly less than the predetermined package length each cycle of operation, said grippers being also mounted for pivotal movement and having opposed web engaging-elements, one comprising a flat .facedzresilient momber and the other comprising a cooperating curved face knurledmetallic member, control :means in-- cluding means for detecting the position of a registrationmark at a predetermined time during the advance of the web, and means responsive to said detecting means and movable into engagement with a portion of said grippers when and only when :a deviation from a predetermined position beyond an allowabletoierance is detected intermittently advancing two webs each having substantially equally spaced registration marks thereon, defining successive package sections, comprising a pair of horizontally and vertically reciprocable grippers for each web, means for operating said grippers simultaneously to normally advance the webs a fixed distance slightly less than the predetermined package length each cycle of operation, control means for each web including means for detecting the position of a registration mark at a predetermined time during the advance of the web, and means responsive to saidcontrol means arranged to cooperate with the respective grippers to increase the advancing movement when and only when a deviation from a predetermined position beyond allowable tolerances is detected as determined by the interception of the, detecting means by the registration mark during said predetermined time for selectively efiecting an additional fixed increment of advance of such web as the grippers approach the end of their normal advancing stroke whereby to obtain a net advance slightly more than the predetermined package length during the same cycle of operation in which said deviation is detected.

' 9. In a duplex machine of the character described, in combination, two Web feeding means for intermittently advancing webs each having 14 substantially equally spaced registration marks thereon, defining successive package sections, comprising a pair of horizontally and vertically reciprccable grippers for each web, means for operating said grippers to normally advance the webs simultaneously a fixed distance slightly less than the predetermined package length each cycle of operation, said grippers being also mounted for pivotal movement, control means for each web including means for detecting the position of a registration mark at a predetermined time during the advance of the webs, and means responsive to said control means including a member movable into engagement with and arranged to cooperate with and eifect pivotal movement of the grippers to increase the stroke as they approach the end of their normal advancing stroke when and only when a deviation from a predetermined position beyond allowable tolerances is detected as determined by the interception of the detecting means by the registration mark during said predetermined time whereby to selectively effect an additional fixed increment of advance of a web to obtain a net advance slightly more than the predetermined package length during the same cycle of operation in which such deviation is detected.

LEWIS B. EATON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,474,748 White Nov. 20, 1923 2,033,857 Smith et a1. Mar. 10, 1936 2,035,201 Smith et a1 Mar. 24, 1936 2,080,292 Webber May 11, 1937 2,199,708 Maxfield May 7, 1940 2,269,532 Howard Jan. 13, 1942 2,338,596 Pitt et a1. Jan. 4, 1944 2,385,229 Patterson Sept. 18, 1945 

